System for handling drain waters of different degrees of contamination

ABSTRACT

A drain water system includes a plurality of containers ( 7-9 ) within a building  1  for receiving respective drain waters differing in degree of contamination. A plurality of building  1  having such containers share a main drain water conduit leads to at least two stations ( 13-15 ) for receiving the respective drain waterd of differing degrees of contamination. Adjusting apparatuses (including, for example, pumps  17 ) sequentially discharge the containers depending upon their degree of drain water contamination. During a certain time period, drain waters of the same degree of contamination will be discharged into the main drain conduit and will then flow to a specific station.

FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a system and a method for transportingdrain water depending upon the degree of drain water contamination.

A system of the above mentioned type is previously known from e.g. SE,B, 409 480, SE 389 881, DE 2 726 527, DE 3 500 130 and FR 2 681 354. Theapplicant's own, still unpublished, Swedish patent application 9503851-9may also be mentioned. Thus, drain water contaminated to differentdegrees is divided and collected in different containers in suchdevices. So-called black water originating from toilets may therefor becollected in one container, blue water from showers, washbasins,bathtubs and similar may be collected in another container and so-calledgreen water from sinks may be collected in yet another container. Thecontainers must thereafter somehow be discharged for taking care of theseparated drain water, wherein it is not possible to utilize theordinary main drain water conduit for a plurality of buildings withoutstopping the separation and the whole point is thereby lost. It istherefor necessary to discharge the containers in question in some otherway by completely separate conduits from the respective container toe.g. a deposit arrangement or to discharge the containers directly intotanks of vehicles and drive the drain water to a suitable location.There are also other possibilities such as exchanging the containerswith empty ones when they are full.

All the actions available by utilizing any of the previously knowndevices for separation of drain water contaminated to different degreesare complicated and therefor expensive and they do not always lead to anoptimum result from the separation point of view.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a system of the typedefined in the introduction, which enables an elimination of the abovementioned disadvantages of previously known such devices, as well as amethod enabling an improved transport of drain water from buildings toan end station to take care of the drain water.

This object is according to the invention achieved by providing a deviceand a method according to the attached independent device and methodpatent claim.

A utilization of the main drain water conduit for transportation of theseparated drain water is enabled by these different characteristicswhile maintaining the separation in the stations, such as purifyingplants, to which the drain water arrives for being taken care of.

Thus, it is by means of such a “sequential drain” possible to transportdrain water with a certain contamination character at a time in the maindrain water conduit from all buildings connected to the same to acertain main drain water station without any mixture of drain water ofsome other contamination character therewith. Some type of container inthe respective building is a prerequisite for such a “sequential drain”.It would have been completely unreasonable to demand that the personsutilizing the different drain water receiving units should use certainunits only during certain time periods. Another advantage with a systemaccording to the invention is that it will be easy to drain the maindrain water conduit when there is a need for renovation work on the maindrain water conduit thanks to the presence of the adjusting apparatus.

According to a preferred embodiment of the invention the first drainwater system section has at least three said parts and at least threesaid containers and the second drain water system section has at leastthree main drain water stations, and the adjusting apparatus is arrangedto obtain discharging of drain water from one of said parts via thecontainer in question in the main drain water conduit and to transportdrain water therein to one of said main drain water stations at a timewhile simultaneously preventing discharging of drain water from theother parts in the main drain water conduit and preventing transport ofdrain water through the main drain water conduit to any of the maindrain water stations associated with said other parts of the firstsystem section. The same good separation of the drain water is in thisway achieved at said stations as in the different buildings connected tothe main drain water conduit, which is of course a great advantage. Itis however pointed out that it is within the scope of the invention thatthere are e.g. three containers in the different buildings and that twocontainers are discharged simultaneously and this drain water istransported in the main drain water conduit, while discharging of athird container is prevented, said both containers of course having amain drain water station in common, and it is in such a case possiblethat the number of main drain water stations are less than the number ofcontainers in a building. For instance, the above discussed “blue” and“green” water should thereby e.g. be able to be transported separatedfrom the transportation of the “black” water.

According to a preferred embodiment of the invention the adjustingapparatus comprises members for an adjustable opening and closing of theflow communication through said conduits between said containers and themain drain water conduit, and according to another preferred embodimentof the invention the adjusting apparatus comprises members for anadjustable opening and closing of the flow communication between themain drain water conduit and the respective main drain water station.Such members of the adjusting apparatus ensure a possibility ofmaintaining optimum separation of drain water with differentcontamination characters from said containers to the main drain waterstations.

According to another preferred embodiment of the invention the adjustingapparatus comprises a pump arranged in each of said conduits betweeneach container and the main drain water conduit, said pump being formedto pump the drain water of the containers in question to the main drainwater conduit during the time periods when discharging of said containeris intended to take place. By utilizing a pump for the transport ofdrain water to the main drain water conduit, it is by easy means ensuredthat the main drain water conduit is provided with drain water of acertain contamination character during certain predetermined timeperiods.

According to another preferred embodiment of the invention each saidconduit between said containers and the main drain water conduit isprovided with a non-return valve for preventing a drain water flow fromthe main drain water conduit up to the respective container through therespective conduit. It is advantageous to arrange such a non-returnvalve in each conduit, while there is otherwise a risk that drain waterwith different contamination characters are being mixed due to that“wrong” drain water rises in one of said conduits and besides anythinkable risk for flowing at any container from the back is in this wayprevented.

According to another very preferred embodiment of the invention itcomprises conduits for connecting the main drain water conduit withmeans for receiving surface water, such as a street inlet or a surfacewater conduit, and members are arranged for an adjustable opening andclosing of these connection conduits. The inventive characteristicsenabling transport of drain water during certain time periods and alsopreventing transport of drain water during other time periods are inthis way utilized in a very advantageous way, since there is apossibility to turn off the main drain water conduit temporarily duringe.g. a few hours relating to transport of drain water at e.g. cloudburstand when there is a risk for flowing in the surface water gutters of thesurface water system, and instead open said connection conduits ondesired positions and letting surface water also flow in the drain waterconduit for reducing the water level in the surface water system. Meansare therefor advantageously arranged to guide the surface watertransported in the main drain water conduit past the main drain waterstations to the location, such as a lake, a stream or similar, where thesurface water normally is being delivered by means of the surface waterconduits in such a situation.

According to a preferred embodiment, which is a further development ofthe last mentioned embodiment, said members associated with theconnection conduits are arranged to open the respective connectionconduit by excess surface water in said means for receiving surfacewater, and that said members of the adjusting apparatus are arranged tosimultaneously with such an opening close the flow communication betweenat least said first container and the main drain water conduit. Theabove described objects with the arrangement of said connection conduitsare realized by such a device. It is also indicated that it is possibleto allow transport of drain water with a less degree of contaminationtogether with surface water in the main drain water conduit, whichhowever possibly rather is to be avoided due to both the mixing and thatit would be advantageous to completely be able to utilize the main drainwater conduit as an extra surface water conduit when there is a risk forflowing in the surface water system, but you could also be more or lessforced to transport drain water in the main drain water conduit if aneed for surface water transport therein takes place during any timethere is an urgent need for transport of water contaminated to a lowerdegree in the main drain water conduit.

According to another preferred embodiment of the invention the adjustingapparatus is arranged to prevent discharging of drain water from allsaid containers in the main drain water conduit during certain timeperiods. The already above discussed draining of the main drain waterconduit is thereby enabled.

According to another preferred embodiment of the invention the adjustingapparatus is formed to realize its adjustment with said time periodsbetween predetermined times in the day. This is advantageous when drainwater in general and drain water with different degrees of contaminationtypically is being mainly produced during certain times of the day.Thus, it is by means of such a design of the adjusting apparatuspossible to discharge the respective container at the time when it ismost preferable.

According to another preferred embodiment of the invention it comprisesmembers for measuring the flow passing by in at least one of saidconduits between the container in question and the main drain waterconduit. By a combination of a dividing of drain water with differentdegrees of contamination in different conduits connected to the maindrain water conduit and an arrangement of said measuring members, itwill be possible to introduce differentiated drain water charges, i.e.to debit the user for producing a certain amount of drain water with acertain degree of contamination, wherein it is possible that it is freeto discharge drain water of another degree of contamination in the maindrain water conduit or that the charge for doing it is another per unitvolume than for the first mentioned drain water.

The advantages with the method according to the invention are clearlyapparent from the discussion above of the device according to theinvention.

Further advantages with the invention as well as advantageouscharacteristics will be apparent from the following description and fromthe other independent patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a description ofa preferred embodiment of the invention cited as an example. In thedrawings:

FIG. 1 is a schematical view illustrating a system according to apreferred embodiment of the invention,

FIG. 2 is a partly cut view transversely in relation to the main drainwater conduit of the system according to FIG. 1 in the vicinity of asurface water gutter, said view being enlarged in relation to FIG. 1,and

FIG. 3 is a simplified view from above of the main drain water conduit,the surface water conduit and a surface water gutter according to FIG. 2of a part of the device according to FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

It is in FIG. 1 illustrated how three different buildings 1 areconnected to a main drain water conduit 2 in common, there are howeverin practise normally more buildings connected to such a main drain waterconduit, which is also indicated at 3. Each building has a first systemsection of the complete drain water system, which is divided into threeparts in this case, which are arranged to receive drain watercontaminated to different degrees from drain water receiving units, saidparts leading to a container each for collecting drain water receivedfrom the respective units. First, second and third such parts with units4, 5 and 6 respectively are only shown in the left building in the veryschematical FIG. 1, and thereto connected first, second and thirdcontainers are indicated by the squares 7, 8 and 9 respectively. Therespective first container 7 is thereby arranged to collect so-called“black” water, i.e. water containing feces and urine originating fromtoilets. The containers 8 and 9 could be arranged for collecting “blue”and “green” water respectively according to the definitions above. It isof course also possible to have more containers, e.g. to separate urineand feces, or only two containers, while in this case one of them isintended for so-called black water, and the other for other drain water.Each container is connected to the main drain water conduit through aconduit 10, 11, 12, which leads to three different stations 13, 14, totake care of drain water of different qualities, and the intention isthat the station 13 will take care of drain water originating from thefirst containers 7, the station 14 will take care of drain water fromthe second containers 8 and the station 15 will take care of drain waterfrom the third containers 9.

The system comprises further an adjusting apparatus comprisingschematically illustrated members 16 for controlling a pump 17 arrangedin each conduit to discharge a container of a certain type, a first, asecond or a third, during certain time periods, in the main drain waterconduit for all buildings, while the pumps belonging to other types ofcontainers are kept turned off. The conduits 10, 11 and 12 have furthera non-return valve 18 each for preventing drain water flow from the maindrain water conduit up to the respective container through therespective conduit.

The system has also members 19 in the form of valves for an adjustableopening and closing of the flow communication between the main drainwater conduit and the respective main drain water station in order toadmit intake of drain water of the type, which is being transported inthe main drain water conduit at a certain moment to the main drain waterstation intended for this drain water type.

It is now also referred to FIG. 2 and 3. The system comprises conduitsfor connecting the main drain water conduit 2 with means for receivingsurface water, more exactly a surface water gutter 21 and indirectlywith a surface water conduit 22, and members 23 are arranged for anadjustable opening and closing of these connection conduits. It is inFIG. 2 illustrated how a surface water gutter 21 has an overflow to theconduit 20 so that surface water may be led to the main drain waterconduit 2 at rising of the water level in the gutter 21 up to theoverflow if the adjusting member 23 opens the communication to the maindrain water conduit 2.

The system has also pumps 24, 25 and 26 in return conduits from thesecond main drain water station 14, the third main drain water station15 and the water course, from which the surface water is intended to bedischarged, respectively for pumping water from these stations and fromthe water course into the main drain water conduit and the surface waterconduit respectively for fire-fighting purposes. These return conduitshave therefor valve members 27 for an optional closing and openingthereof. The possibility to fight fires will now briefly be described,although it is not the object of the present invention, due to that thepresent invention by means of the sequential drain water transportenables use of the drain water system in order to fight fires. Thus, themain drain water conduit 2 and the surface water conduit 22 havearranged valve members 28 and 29 respectively downstream of therespective surface water gutter 21, said valve members may be closedwhen there is a desire for filling the respective surface water gutterwith water for fire-fighting purposes. There are further specific“outtakes” 30 from the main drain water conduit, alternatively thesurface water conduit, for fire-fighting purposes by repumping water viaany of the pumps 24, 25 and 26. Use of the main drain water conduit isenabled in order to fight fires due to that it may be determined duringwhich time periods different types of drain water is being transportedin the main drain water conduit, since it is possible to arrange thatonly water of a quality acceptable for fighting fires is present in thedrain water conduit when there is a desire for such fire-fighting, i.e.at least the communication between said first container 7 and the maindrain water conduit through the conduits 10 is closed.

The function of the system according to the invention appears from thediscussion above. It may be added that only about 5% of the volume drainwater delivered to a main drain water conduit is in this way so-calledblack water, so that it in principle would be enough transporting suchblack water during a time period of one hour a day in the main drainwater conduit. Two time periods a day may however be chosen in practisefor discharging the first containers 7, e.g. a short period in themorning and a short period late at night. The remaining time isdisposable for transport of water contaminated to a less degree in themain drain water conduit or surface water therein. Thus, the timeperiods during which drain water is pumped from the containers 8 and 9will be substantially longer—at least concerning the overall pumpingtime a day. A member 31 for measuring the drain water volume passingthrough the respective conduit 10 is indicated in the left building forenabling debit of the released volume of the specific drain waterquality.

The invention is of course not in any way limited to the abovedescribed, preferred embodiment, but a plurality of possibilities ofmodifications thereof should be apparent for a man skilled in the artwithout departing from the invention idea, such as it is described inthe attached claims.

A plurality of possible modifications have already been touched uponearlier and it may here e.g. be added that it is of course within thescope of the invention to provide a plurality of main drain waterconduits, to which different buildings are connected, and which mayemerge in a common main drain water conduit, or a plurality of maindrain water conduits could lead to one or each of the main drain waterstations. It would also be possible to combine the device according tothe invention with conventional drain water systems, so that there aredrain water systems without any separation parallel to the deviceaccording to the invention, wherein it would be possible to lead suchdrain water to the main drain water station arranged to take care of thedrain water contaminated to a high degree.

What is claimed is:
 1. A drain water system having a section located ina building with a first container arranged to receive first drain watercontaminated to a relatively high degree, and a second containerarranged to receive second drain water normally contaminated to a lowerdegree, characterized in that the drain water system has a main drainwater conduit for a plurality of buildings each provided with one saidsection, the first and second containers are each connected to the maindrain water conduit via respective conduits (10-12), said main drainwater conduit leading to a plurality of stations comprising a first anda second station to receive the first and second drain waters,respectively, an adjusting apparatus is arranged to discharge drainwater from said first containers into the main drain water conduit andto transport drain water therein to said first station during first timeperiods while simultaneously preventing discharging of drain water fromthe second containers into the main drain water conduit and to dischargedrain water from the second containers into the main drain water conduitand to transport drain water therein to the second station during secondtime periods while simultaneously preventing discharging of drain waterfrom the first container into the main drain water conduit.
 2. A systemaccording to claim 1, characterized in that the adjustaing apparatuus isarranged to discharge drain water from one of the containers into themain drain water conduit (2) and to transport drain water therein to oneof said stations at a time while simultaneously preventing dischargingof drain water from the other containers into the main drain waterconduit and preventing transport of drain water through the main drainwater conduit to the other of the stations.
 3. A system according toclaim 1, characterized in that the adjusting apparatus comprises members(17) for an adjustable opening and closing of the flow communicationthrough said conduits (10-12) between said containers (7-9) and the maindrain water conduit (2).
 4. A system according to claim 1, characterizedin that the adjusting apparatus comprises members (19) for an adjustableopening and closing of the flow communication between the main drainwater conduit (2) and the respective stations (13-15).
 5. A systemaccording to any of the claim 2, characterized in that the adjustingapparatus comprises a pump (17) arranged in each of said conduits(10-12) between each container (7-9) and the main drain water conduit,said pump being formed to pump the drain water of the containers to themain drain water conduit (2) during the time periods when discharging ofeach said container is intended to take place.
 6. A system according toclaim 1, characterized in that each said conduit (10-12) between saidcontainers (7-9) and the main drain water conduit (2) is provided with anon-return valve (18) for preventing a drain water flow from the maindrain water conduit up to the respective container through therespective conduit.
 7. A system according to any of the claim 2characterized in that it comprises conduits (20) for connecting the maindrain water conduit (2) with means (21, 22) for receiving surface water,and that members (23) are arranged for an adjustable opening and closingof these connection conduits.
 8. A system according to claim 7,characterized in that said members (23) associated with the connectionconduits (20) are arranged to open the respective connection conduit byexcess surface water in said means for receiving surface water, and thatsaid members of the adjusting apparatus are arranged to simultaneouslywith such an opening close the flow communication between at least saidfirst container (7) and the main drain water conduit (2).
 9. A systemaccording to claim 8, characterized in that the adjusting apparatus isarranged to obtain closing of the flow communication between all saidcontainers (7-9) and the main drain water conduit (2) by means of saidmembers on opening of a flow communication between said means (21, 22)for receiving surface water and the main drain water conduit through therespective connection conduit (20).
 10. A system according to claim 1,characterized in that the adjusting apparatus is arranged to preventdischarging of drain water from all said containers (7-9) to the maindrain water conduit (2) during certain time periods.
 11. A systemaccording to claim 1, characterized in that it comprises members (31)for measuring the flow passing by in at least one (10) of said conduits(10-12) between the first container and the main drain water conduit.